A safety monitoring board said it had seen serious and opportunistic infections in studies involving the drug and that some were fatal.

At the end of last year, Roche had said a late-stage trial of the experimental rheumatoid arthritis drug showed it significantly reduced the signs and symptoms of the painful joint disease.

Rheumatoid arthritis is an autoimmune disease characterized by inflammation that leads to stiff, swollen and painful joints. It affects some 20 million people, according to the National Rheumatoid Arthritis Society.

The drug is still being evaluated for relapsing multiple sclerosis and a Phase II study is on-going, Roche said.